Stephen Larbi, who joined City Year in Providence as a program director after graduating from the University of Rhode Island, is new to slam poetry, but he’s already hooked.

“I used to try to rap, and this is another way to express myself,” Larbi says later in the evening. “I’m addicted to performing. It’s like a hunger — you keep feeding it. You never know who you will impact.”

That’s how each of the 400 or so performance poets who are descending this week on Boston feel about their craft. For the second time in three years, the city is hosting the National Poetry Slam, a team-based tournament that turns the art of the spoken word into a blood sport in which the competitors voluntarily shed their own blood, metaphorically speaking.

Simone Beaubien is the host city director of this year’s National Poetry Slam, as she was in 2011. “You do think of slam as a sport sometimes, like March Madness, with the seeding,” says Beaubien, who has also competed on a national level in pinball and Ultimate Frisbee. “But in sports you age out at a certain point. As a writer, you just keep getting better.”

For nearly a decade, Beaubien, 35, has been SlamMaster of the Cantab Lounge’s weekly Wednesday night poetry slam and open mike, a local institution for more than 20 years and a widely recognized hub of the international performance poetry community. Anchored by the Cantab and the Lizard Lounge, home of another long-running weekly slam, Greater Boston hosted the most successful National Poetry Slam (NPS) to date in 2011, with more than 6,000 people attending the week’s events and a sellout at every venue — a first in the 24-year-history of the tournament.

When Chicago, this year’s original host city, bowed out because of a conflict with Brave New Voices, the youth-oriented poetry slam which, like the adult version, originated in the Windy City, Beaubien asked her organizational team whether they’d be willing to step in and do it again. (August is like “summer camp” season for the poetry crowd; this week, Pittsfield is hosting the fifth annual WordXWord Festival.)

“It’s crazy, kind of like running the Olympics back to back,” says the director, a paramedic by trade, of bringing the NPS back to Boston so soon. “But every person said, ‘Yes — I know how to make my part of this event better.’ ’’

Nora Meiners is this year’s “venue liaison,” helping book the NPS stages, including first-time partners at Oberon, Johnny D’s, Lesley University, and Cambridge College. The finals take place Saturday at the Berklee Performance Center.

Meiners, a PR rep for a game and puzzle company, is also a first-time Nationals competitor, having made this year’s Boston Poetry Slam team (based at the Cantab) after dropping into her first poetry slam there just a couple of years ago.

A single mother of a 5-year-old, she was looking for a creative outlet for the nights when her son was with his father when she settled on the slam scene.

“The first year, my hand would shake,” she says. “But the value I got [from performing] was bigger than my own personal fear of getting onstage.”

She’s still pinching herself that she emerged from the grueling qualifying rounds in January and February to become one of this year’s five Cantab team members.

“The way I look at it, there are probably a good 150-200 really active slam poets in Boston vying for about 10 spots” between the Cantab and Lizard Lounge teams, she says.

Slam contestants have three minutes to deliver their original poems. No props or music are allowed. Five judges, chosen from the audience at the beginning of the evening, score each work on a scale of 0.0-10.0; the lowest and highest scores are thrown out, and the final score is the average of the three remaining.

Though the camaraderie is palpable — acquaintances greet each other like best friends from childhood — audiences are encouraged to be vocal. Usually that means words of support for the performer and good-natured needling of the judges when scores are called, but there’s often mild heckling too.

It’s not the city’s academic environment that has made Boston one of the core communities for slam poets, says Beaubien. “It has more to do with the fact that we have an enormous population of young people in the city at times in their lives when they’re looking to grow, and looking for artistic stimuli.”

There is incredible diversity at a poetry slam; the only thing typical is that there’s nothing typical about the participants. At the Lizard Lounge, Providence’s Aaron Samuels recited a poem about growing up half-black, half-Jewish, while a newcomer from Lowell’s Mill City team, calling herself Princess Chan, earned a near-perfect score for her devastating poem about immigration and personal trauma.

Many of the participants are young, but not all. When Beaubien was first convinced to compete by the late Jack McCarthy (who died in January at 73), she was inspired by “seeing someone like Billy Barnum, one of the original Boston poets, almost every week. You can see the last 50 years of writing on the same stage. It’s mind-blowing,” she says.

The voices that make up the poetry slam community teach each other and their audiences about multiplicity, says Beaubien, who was born in Lowell and grew up in Chelmsford.

“This particular community — not just in Boston but the nationwide slam community — for me is at the forefront of all the difficult discussions we have about being in America,” she says. She cites the aftermath of the Trayvon Martin killing as one such topic.

“I consider myself really lucky to be a part of the community, to have the opportunity to understand and share with people who have a very different experience of living in America than I do. It’s almost like we’re at the forefront of communication.”

At the Lizard Lounge recently, the competing teams were effectively wrapping up their exhibition season in preparation for the NPS “playoffs.” The teams, including one from New York, were facing off in the “NorthBeast” regionals, representing a New England-area coalition that fosters spirited competition locally but a welcome solidarity across team rosters when it comes to the Nationals.

The poetry, as it so often does, ranged from broadly topical to deeply confessional, from laugh-out-loud funny to the kind of precisely worded observation that can stun the room into silence, or a chorus of murmuring admirers.

“We feel the [expletive] other people don’t want to feel,” said Christopher Johnson, a boisterous regular from Providence in long dreadlocks and a Fela Kuti T-shirt. As he took the microphone in the center of the basement room, walking across a well-worn Oriental rug, someone spilled a drink.

He was quick with a joke. “I have that effect on women,” he said.

Meiners, who was in the audience, might have been speaking for all of her colleagues when she said a few days later, “Every time I get onstage, I just want to be as authentic as possible. It is my detail, how it sits with me, my emotional response to it. I can’t tell you how to have an emotional response.”

As she prepared to compete in the Aug. 13 preliminary bout — the Boston Poetry Slam Team has drawn opponents from Seattle, San Diego, and Utah — she said she couldn’t wait.

“There are no guarantees I get to do this again,” Meiners said. “I’m enjoying every second.”